1. Field of the Invention
This invention relates to a printing method, printing system and printing apparatus for printing a variety of information such as images and characters to a recording medium, such as a card, and more particularly to a printing method, printing system and printing apparatus that are capable of switching printing methods to print information to the entire surface of the recording medium.
2. Description of the Related Art
Conventionally, thermal transfer method printing apparatuses that record the desired images and characters by thermally transferring using a thermal head via a thermal transfer film to a recording medium are used to create card shaped recording medium, like credit cards, cash cards, license cards and ID cards. An example can be found in Japanese disclosure Tokkaihei 9-131930 (U.S. Pat. No. 5,959,278) which teaches a direct transfer method printing apparatus that directly transfers images and characters to a recording medium via thermal transfer film. The use of a thermal sublimate ink has the benefit of attaining high quality images because this type of ink is more expressive. However, a receptive layer to receive ink on the surface of a recording medium to which images, etc., are transferred is an essential element to make this method of printing possible. Therefore, there is the problem that the types of recording medium that can be used is limited, or else it is necessary to form a receptive layer upon the surface of a recording medium.
Generally, cards made of polyvinyl chloride (also known as PVC cards) are widely used as a recording medium because they can receive thermal sublimate ink. However, due to the fact that harmful substances are generated when these cards are burned, consideration is being given to switching to cards made of polyethylene terephthalate (also known as PET cards). Furthermore, in recent years, there are card shaped media that have IC chips or antennae embedded therein. Such IC cards are used in a variety of fields. Because there is an object embedded in the card, the surface of the card ends up being uneven which results in image transfer problems.
Japanese patent number 2870574 teaches the technology of a thermal transfer method printing apparatus that overcomes the aforementioned problems in an indirect transfer method printing apparatus that transfers an image to an intermediate transfer medium once, then transfers that image again to the recording medium. According to this method, it is possible to overcome the problems of the direct transfer method, such as the limit to the type of recording medium, related to the receptive layer, or the problem of the transferring of images to an uneven surface of the recording medium, both of which are considered to be demerits of direct transfer printing. Furthermore, this method has the advantage of being easier to printing to the entire surface of the card shaped recording medium compared to the direct transfer method.
However, running costs associated with the intermediate transfer method are higher than those for the direct transfer method because an intermediate transfer medium must be used. Printing also takes longer. Furthermore, depending on the design of the card, even if the entire front surface is required for printing, often times the back side is used only to print precautions for card use. Therefore, there are fewer cases requiring printing to the entire surface, so there are merits and demerits for both methods of printing.
Therefore, if there were a printing apparatus that can switch between the printing methods of direct transfer method and the indirection transfer method to print images to a recording medium according to the characteristic of the recording medium, such as quality of the material of the recording medium, like PVC or PET, or whether or not it includes IC elements, and to the objective of use of the final print, it would be possible to print using the method best suited for each particular recording medium. This, in turn, would reduce the running costs that are associated with printing. It would also be possible to conceive that such a printing apparatus would become widely used in the future.
Currently, in the card market, there is a greater demand for esthetic reasons to be able to print to the entire surface of card-shaped recording medium. As a result, this type of printing is becoming more common.
However, in order to print to the entire surface of the card-shaped recording medium using the direct transfer method, print data, such as an image, must be generated or created in the same size as a normal card-shaped recording medium. Then that image data can be directly printed to that card-shaped recording medium. On the other hand, if using the indirect transfer method as described in the Japanese patent 2870574 mentioned above, it is difficult to position the image data region that is formed on the intermediate transfer film and the card-shaped recording medium because of the reducing that occurs in that intermediate transfer film. That makes is necessary, then, to generate or create image data to form on the intermediate transfer film that is larger than the card-shaped recording medium.
Specifically, to use a printing apparatus configuration that comprises both methods to print (or form images) to the entire surface of a card-shaped recording medium, it is necessary to have two different sizes of image data. More specifically, one size for each type of printing method would be required, even if the targeted image data is the same. This is very troublesome, and it results in higher costs in issuing cards.